Operators have been looking at a number of ways to address the spectrum shortage issue and are increasingly looking towards the use of unlicensed spectrum as a solution. In some implementations, a Long Term Evolution (LTE) air-interface can be used in unlicensed spectrum. The general technology variant of LTE that can be used in unlicensed spectrum is referred to as licensed-assisted access in LTE (LAA-LTE). In some cases, LAA-LTE can use a licensed carrier as a primary cell (PCell) and an unlicensed carrier as a secondary cell (SCell). In some cases, cross-carrier scheduling can be used to schedule transmission on the unlicensed carrier. In a licensed-assisted operation, a transmission grant for a transmission on the unlicensed carrier can be transmitted on the licensed carrier.
Like reference numbers and designations in the various drawings indicate like elements.